Looking forward the progressive development of the electrical and information related device, light, thinness, short and small have almost been the common consensus of the public, so as to that the Micro Electro-Mechanical Systems (MEMS) are widely used in many kinds of novel electric and information related devices. In the Micro Electro-Mechanical Systems, all related science theorem and technique, such as material, optics, mechanism, electric, electronics, system control, chemical engineering, dynamics, etc., most of the micro constructions or elements are produced by semi-conduct production techniques, and further fitted and connected with each other to produce different systematized products. Meanwhile, in a wide viewpoint, the technical application also widely expands to the fields of national defense industry, biological and medical test, consumer electrical product, and aviation technique, etc.
Besides, due to the minimization of the systems, the troubles about traditional design limited by working platform dimension and sampling scales, etc. can be overcome and progressively improved to lead the current technical development and absorb more and more skilled people participating in this research field.
Moreover, micro fluid has already played an important role in Micro Electro-Mechanical Systems, so that the relative applications are also innumerable, such as light portable biological and medical test equipment, medicine test equipment, chemical analysis test device, medicine efficiency estimation, etc., also almost can not depart from the application field of micro fluid.
From above description, we can further realize that the flowing, mixing and sampling are the most important procedures in the micro fluid application, especially for the mixing rate. Accordingly, we can quote Fick's Law and the characteristics of material being phobic or tending to liquid, and provide further statement for the invention.
According to Fick's Law, different liquids are mixed from the diffusion action of molecules, and the larger surface area the different liquids touch with each other, the higher mixing rate is generated.
In addition, a material tending to a liquid means a contact angle between the material and the liquid is less than 90 degree, and a material phobic to a liquid means a contact angle between the material and the liquid is greater than 90 degree.
Under the base of Fick's Law and the material characteristics, let us go back to current application. In general, different liquids are usually mixed through the methods of generating three-dimensional fluid field and turbulent by stirring. However, in a micro liquid flowing system, liquids are usually not able to mixes effectively due to the limitation of the micro working platform dimension and large viscous coefficient.
As we all know, there are many methods, such as producing pressure gradient, thermal deviation, electrostatic, continuous electro-wetting effect (CEW) or magnetic fields, etc., used for driving fluids, especially for liquids, flowing within micro pipes or channels. While, it is still necessary to use the methods of producing vapor pressure deviation by heating, generating energy deviation by setting electric poles based on microelement production techniques, and generating voltage deviation by electrolyte electrolysis. Thus, it is not only necessary to install additional peripheral components, but also difficult to control the flowing situation of the liquids.